The cutting head of an electric shaving system conventionally comprises a shear foil and an inner, movable cutter. The foil is a thin, flexible member that has a plurality of perforations or apertures therethrough for receiving hairs and stubble to be shaved. The corresponding cutter is positioned in contact with a rear surface of the foil and typically comprises a plurality of separate blades, but may also include a cutting foil or other suitable cutting device. Regardless of the specific configuration, the cutter vibrates or otherwise reciprocates back and forth over the apertures in the foil.
During a shaving operation, the foil is brought into intimate contact with the skin. As the shaving system is moved about an area to be shaved, hair and stubble pass through the apertures in the foil and are trimmed by the movable cutter, which repeatedly crosses the apertures in the foil. As such, the closeness, comfort and quality of the resulting shave are affected, at least in part, by the design of the foil.
In particular, the size, shape and orientation of the apertures in the foil affect the performance of the shaving operation. Thus, previous foils have been provided with repeating patterns of circular, rectangular, hexagonal and other geometric shaped apertures in an attempt to find a pattern that will provide a close and comfortable shave. However, hairs tend to grow in distinctly different directions. Moreover, hairs tend to exhibit differences in size.